Images of Chinese troops massing near Hong Kong are feeding fears of an impending crackdown on pro-democracy protesters, Axios World editor Dave Lawler writes.

• Why it matters: China's next move will be dangerous, no matter what. If China repeats Tiananmen Square, the world turns on the regime. If Xi Jinping holds back, he looks weak and worsens a political standing that has already been shaken by a slowing economy. 

Between the lines: Allowing Hong Kong's dramatic displays of dissent to rage on is intolerable for the Communist Party.

• But a crackdown on the scale of Tiananmen Square 30 years ago would risk steep economic repercussions.

The latest: Riot police swarmed into Hong Kong's international airport last night and dispersed protesters who caused two days of chaos and cancellations at the world’s eighth busiest airport.

• Carrie Lam, Hong Kong’s Beijing-approved chief executive, said the city was  being "smashed to pieces" and is on "the brink of no return."
• President Trump tweeted: "Our Intelligence has informed us that the Chinese Government is moving troops to the Border with Hong Kong. Everyone should be calm and safe!" OK, then!

China’s propaganda machine has raged against the protesters, with officials claiming the protests contain "sprouts of terrorism" and the "black hand" of foreign intervention.

• "They're certainly putting down rhetorical markers that would justify a heavy-handed intervention," says Dan Kliman of the Center for a New American Security.

The big picture: Xi has spent six years systematically clamping down on dissent, and attempting to solidify Beijing's control over all of China.

• "The biggest risk is for Xi himself," Kliman says.

Go deeper: The latest.

• CFR President Richard Haass writes for Axios Expert Voices, "Hong Kong protests assert the freedoms China seeks to constrain."

"[M]ore than 1 in 10 Americans — 34 million people — are living in rapidly heating regions, including New York City and Los Angeles," according to an analysis of 3,107 counties in the Lower 48 states by The Washington Post.

• The UN "warns that if Earth heats up by an average of 2 degrees Celsius, virtually all the world’s coral reefs will die; retreating ice sheets in Greenland and Antarctica could unleash massive sea level rise."
• 71 counties have already hit the 2°C mark.

Alaska is the fastest-warming state, the Post analysis found.

• Higher winter temperatures made Rhode Island the first state in the Lower 48 whose average temperature rise eclipsed 2°C.
• "Other parts of the Northeast — New Jersey, Connecticut, Maine and Massachusetts — trail close behind."

Go deeper: Axios' Kim Hart, "Rising global temperatures wreak havoc on urban 'heat islands.'"

What's new: "U.S. mortgage debt reached a record in the second quarter, exceeding its 2008 peak as the financial crisis unfolded," The Wall Street Journal's Harriet Torry reports (subscription).

• What's happening: "Alongside higher home prices, a factor ... could be homeowners tapping into home equity for cash when they refinance."
• "Refinancing accounted for about half of new mortgages in the second quarter ... a 'mini refinancing boom.'"

"The two staff members who were guarding the jail unit where Jeffrey Epstein apparently killed himself fell asleep and failed to check on him for about three hours, then falsified records to cover up," the N.Y. Times reports:

• The two guarding him "had not looked in on Mr. Epstein for about three hours before he was found."
• "The warden, Lamine N’Diaye, will be transferred to a Bureau of Prisons office in Philadelphia."

What's new: City governments, following the example of major brands, are now tapping into data from social streams to keep tabs on residents' chatter and complaints, Axios' Kim Hart writes.

• Why it matters: Social media creates a wide-ranging sensor network of sorts that helps cities direct resources to what residents actually care about. But it can also be surprising for users who don't expect city staff to be paying attention.

ZenCity, a Tel Aviv-based, Microsoft-backed startup, sells an AI-powered sentiment analysis tool designed to track citizen opinions so cities can gauge how they are performing.

• It works with 75 communities including Houston, which gauges residents' responses to changes in city services, such as a garbage pick-up schedule changes, and a project equipping free WiFi on buses and trains.
• Cary, N.C., used ZenCity data to monitor how residents felt about the fleet of electric scooters that quickly appeared on sidewalks.

Subscribe to Kim Hart's weekly Axios Cities newsletter. (Out this afternoon!)

"Fear sells even better than sex."

The N.Y. Times launches the 1619 Project, "observing the 400th anniversary of the beginning of American slavery."

• Late August of 1619 "was when a ship arrived at Point Comfort in the British colony of Virginia, bearing a cargo of 20 to 30 enslaved Africans."
• Why it matters: The project "aims to reframe the country’s history, understanding 1619 as our true founding, and placing the consequences of slavery and the contributions of black Americans at the very center of the story we tell ourselves about who we are."

Worthy of your time (subscription).

Today marks the start of a one-year window in New York allowing molestation victims to file lawsuits that had previously been barred by the statute of limitations, AP's David Klepper writes.

• The Catholic Church, the Boy Scouts, public school districts and hospitals are among the expected targets.

Why it matters: Institutions that have long cared for children are girding for what could be a devastating financial blow.

• A similar law, passed in California in 2002, resulted in Catholic dioceses there paying $1.2 billion in legal settlements.

Snap Inc. this fall will launch a new version of its Spectacles sunglasses, able to capture photos and videos and upload them directly to Snapchat, Reuters reports.

• Spectacles 3 "will cost $380, almost twice the $200 cost of the previous version."
• "It will have dual cameras to add depth and dimension to photos and videos."
• "After uploading the content to ... Snapchat, users can add new lighting, landscapes and three-dimensional effects."

"Forget hot dogs and s’mores: Farm-to-table cooking classes are some of the most popular new offerings at summer camp this year," the Boston Globe's Kay Lazar writes.

• At New England Base Camp in Milton, Mass., 14-year-old campers are whipping up quiche and sautéed vegetables, "followed by panini sandwiches featuring tomatoes grown at the camp, capped off by apple crisp pie drizzled with honey produced from the camp’s beehives."

Why it matters, per The Globe: "A generation of foodie kids raised on 'Chopped' ... and 'MasterChef Junior' wants serious cooking lessons."

• "There’s a growing curiosity ... fueled by the resurgence of farmers’ markets, school gardens, and an emphasis on eating local."